The present invention relates generally to an imaging apparatus and layers for components thereof, and for use in electrostatographic, including digital, apparatuses. The layers herein are useful for many purposes including layers for transfix films or transfuse films, and the like. More specifically, the present invention relates to layers comprising a hybrid material of a fluoroelastomer and polyamino polysiloxane material. In embodiments, the layers are useful for layers of transfix or transfuse members. In embodiments, the layer is useful as an outer layer of a transfix member. In embodiments, there may be included an optional intermediate layer between the transfix substrate and outer hybrid layer. The layers of the present invention may be useful in films, belts or the like members, and may be used in xerographic machines, especially color machines.
In a typical electrostatographic reproducing apparatus such as an electrophotographic imaging system using a photoreceptor, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a photosensitive member and the latent image is subsequently rendered visible by the application of a developer mixture. One type of developer used in such printing machines is a liquid developer comprising a liquid carrier having toner particles dispersed therein. Generally, the toner is made up of resin and a suitable colorant such as a dye or pigment. Conventional charge director compounds may also be present. The liquid developer material is brought into contact with the electrostatic latent image and the colored toner particles are deposited thereon in image configuration.
The developed toner image recorded on the imaging member can be transferred to an image receiving substrate such as paper via an intermediate transfer member. Alternatively, the developed image can be transferred to an intermediate transfer member from the image-receiving member via another transfer member. The toner particles may be transferred by heat and/or pressure to an intermediate transfer member, or more commonly, the toner image particles may be electrostatically transferred to the intermediate transfer member by means of an electrical potential between the imaging member and the intermediate transfer member. After the toner has been transferred to the intermediate transfer member, it can then be transferred to the image receiving substrate, for example by contacting the substrate with the toner image on the intermediate transfer member under heat and/or pressure. Alternatively, the developed image can be transferred to another intermediate transfer member such as a transfix or transfer member. A transfix or transfuse member uses heat associated with the transfer member in order to both transfer and fix or fuse the developed image to a copy substrate.
Intermediate transfer members, including transfix or transfuse members, enable high throughput at modest process speeds. In four-color photocopier systems, the transfer member also improves registration of the final color toner image. In such systems, the four component colors of cyan, yellow, magenta and black may be synchronously developed onto one or more imaging members and transferred in registration onto a transfer member at a transfer station.
In electrostatographic printing machines in which the toner image is transferred from the transfix member to the image receiving or copy substrate, it is important that the transfer of the toner particles from the transfix member to the image receiving substrate be substantially 100 percent. Less than complete transfer to the image receiving substrate results in image degradation and low resolution. Completely efficient transfer is particularly important when the imaging process involves generating full color images since undesirable color deterioration in the final colors can occur when the color images are not completely transferred from the transfer member.
Thus, it is important that the transfix member surface has excellent release characteristics with respect to the toner particles. Conventional materials known in the art for use as transfix members often possess the strength, conformability and electrical conductivity necessary for use as transfix members, but can suffer from poor toner release characteristics, especially with respect to higher gloss image receiving substrates. When heat is associated with a transfer member, such as in the case of a transfix member, the transfix member must also possess good thermal conductivity in addition to superior release characteristics. Also, there is a need for mechanical strength for wear resistance. A transfix member undergoes multiple cycling during use.
In addition, in the event that electrically conductive fillers are needed to build electrical and thermal conductivities, and/or mechanical strength, it is necessary that the fillers be compatible with the materials used in the transfix member. Similarly, if release fluids are used, the materials in the transfix member and the fillers, if used, must be compatible with the release fluid materials. Also, the fillers, if used, and the materials in the transfix members must be chemically compatible with toners or liquid developers used in the electrostatographic apparatus.
Conventionally, for transfuse or transfix applications, a conformable member is used. Silicone is a very popular outer layer for transfix and transfuse members, especially for transfuse or transfix belts or films. Silicone possesses excellent toner release characteristics. However, the major drawback to using silicone as the outer layer is the short performance life. This is especially true in liquid marking applications, wherein the carrier fluid swells the silicone layer and results in excessive belt wear. The mechanical property of the belt deteriorates significantly, resulting in short belt life. For dry powder marking, it is believed that the mechanism of toner release requires extrusion of the silicone oligomer. The extruded oligomer serves as the release agent. However, as the oligomer is extruded, the property of the belt changes and the performance life of the belt is reduced. The belt becomes less compliant and its release function deteriorates. The extrusion degrades the belt simultaneously.
One countermeasure to the above problems is to use a fluoroelastomer surface for the transfuse member. In fact, many forms of fluoroelastomers are much stronger than silicone. However, the fluoroelastomers can usually not release toner on their own. A,release agent management (RAM) system has to be introduced in order to overcome this shortfall. The potential problem with introduction of a RAM system is that oil contamination of the entire transfuse subsystem can occur.
Further, it is desirable to provide a print engine that is targeted for all of office, production, color and offset market. Such a print engine would need to be able to print on many different types of substrates, and have the capability to mark papers of different weight and different roughness, such as wallpapers, textiles, foils, and other papers. In electrostatography, extended substrate, latitude may be accomplished through the transfuse process where the toner images are transferred and fused simultaneously. Since fusing is accomplished on the transfuse member, the member should be stiff, compliant and have sufficient toner release characteristics for the outer surface as well.
Therefore, the requirements for transfuse surfaces are demanding and sometimes conflicting.
U.S. Pat. No. 4,853,737 discloses electrostatographic rollers having an outer layer comprising a cured fluoroelastomer containing pendant polydiorganosiloxane segments that are covalently bonded to the backbone of the fluoroelastomer.
U.S. Pat. No. 5,361,126 discloses an imaging apparatus including a transfer member including a heater and pressure-applying roller, wherein the transfer member includes a fabric substrate and an impurity-absorbent material as a top layer. The impurity-absorbing material can include a rubber elastomer material.
U.S. Pat. No. 5,337,129 discloses an intermediate transfer component comprising a substrate and a ceramer or grafted ceramer coating comprised of, integral, interpenetrating networks of haloelastomer, silicon oxide, and optionally polyorganosiloxane.
U.S. Pat. No. 5,340,679 discloses an intermediate transfer component comprised of a substrate and thereover a coating comprised of a volume grafted elastomer, which is a substantially uniform integral interpenetrating network of a hybrid composition of a fluoroelastomer and a polyorganosiloxane.
U.S. Pat. No. 5,480,938 describes a low surface energy material comprising a volume grafted elastomer which is a substantially uniform integral interpenetrating network of a hybrid composition of a fluoroelastomer and a polyorganosiloxane, the volume graft having been formed by dehydrofluorination of fluoroelastomer by a nucleophilic dehydrofluorinating agent, followed by a hydrosilation reaction, addition of a hydrogen functionally terminated polyorganosiloxane and a hydrosilation reaction catalyst.
U.S. Pat. No. 5,366,772 describes a fuser member comprising a supporting substrate, and a outer layer comprised of an integral interpenetrating hybrid polymeric network comprised of a haloelastomer, a coupling agent, a functional polyorganosiloxane and a crosslinking agent.
U.S. Pat. No. 5,456,987 discloses an intermediate transfer component comprising a substrate and a titamer or grafted titamer coating comprised of integral, interpenetrating networks of haloelastomer, titanium dioxide, and optionally polyorganosiloxane.
U.S. Pat. No. 5,848,327 discloses an electrode member positioned near the donor member used in hybrid scavengeless development, Wherein the electrode members have a composite haloelastomer coating.
U.S. Pat. No. 5,576,818 discloses an intermediate toner transfer component including: (a) an electrically conductive substrate; (b) a conformable and electrically resistive layer comprised of a first polymeric material; and (c) a toner release layer comprised of a second polymeric material selected from the group consisting of a fluorosilicone and a substantially uniform integral interpenetrating network of a hybrid composition of a fluoroelastomer and a polyorganosiloxane, wherein the resistive layer is disposed between the substrate and the release layer.
U.S. Pat. No. 6,037,092 discloses a fuser member comprising a substrate and at least one layer thereover, the layer comprising a crosslinked product of a liquid composition which comprises (a) a fluorosilicone, (b) a crosslinking agent, and (c) a thermal stabilizing agent comprising a reaction product of (i) a cyclic unsaturated-alkyl-group-substituted polyorganosiloxane, (ii) a linear unsaturated-alkyl-group-substituted polyorganosiloxane, and (iii) a metal acetylacetonate or metal oxalate compound.
U.S. Pat. No. 5,537,194 discloses an intermediate toner transfer member comprising: (a) a substrate; and (b) an outer layer comprised of a haloelastomer having pendant hydrocarbon chains covalently bonded to the backbone of the haloelastomer.
U.S. Pat. No. 5,753,307 discloses fluoroelastomer surfaces and a method for providing a fluoroelastomer surface on a supporting substrate which includes dissolving a fluoroelastomer; adding a dehydrofluorinating agent; adding an amino silane to form a resulting homogeneous fluoroelastomer solution; and subsequently providing at least one layer of the homogeneous fluoroelastomer solution to the supporting substrate.
U.S. Pat. No. 5,840,796 describes polymer nanocomposites including a mica-type layered silicate and a fluoroelastomer, wherein the nanocomposite has a structure selected from the group consisting of an exfoliated structure and an intercalated structure.
U.S. Pat. No. 5,846,643 describes a fuser member for use in an electrostatographic printing machine, wherein the fuser member has at least one layer of an elastomer composition comprising a silicone elastomer and a mica-type layered silicate, the silicone elastomer and mica-type layered silicate form a delaminated nanocomposite with silicone elastomer inserted among the delaminated layers of the mica-type layered silicate.
Therefore, it is desired to provide a transfix member that possesses the qualities of conformability for copy quality and latitude, and also is tough for wear resistance. A further desired characteristic is for a transfer member to have a reduced susceptibility to swelling in the presence of release oils or in the presence of liquid marking materials. An additional desired property for a transfix or transfuse member having heat associated therewith, is for the transfix member to be thermally stable for conduction for fusing or fixing. In addition, it is desired to provide a transfuse member that can be used to transfer and fuse toner material to a variety of copy substrates. It is further desirable to provide a transfix member having high tensile strength, while providing good release characteristics. It is also desirable to provide a transfix member having long life.
The present invention provides, in embodiments: an apparatus for forming images on a recording medium comprising: a) a charge-retentive surface to receive an electrostatic latent image thereon; b) a development component to apply a developer material to the charge-retentive surface to develop the electrostatic latent image to form a developed image on the charge-retentive surface; c) a transfer component for transferring the developed image from the charge-retentive surface to an intermediate transfer component; d) an intermediate transfer component for receiving the developed image from the transfer component and transferring the developed image to a transfix component; and e) a transfix component to transfer the developed image from the intermediate transfer component to a copy substrate and to fix the developed image to the copy substrate, the transfix component comprising: i) a transfix substrate, and ii) an outer layer comprising a hybrid composition comprising polyamino polysiloxane and fluoroelastomer, and iii) a heating member associated with the transfix component.
The present invention further provides, in embodiments: a transfix member comprising: a) a transfix substrate, and thereover b)an outer coating comprising a hybrid composition comprising polyamino polysiloxane and fluoroelastomer, and c) a heating member associated with the transfix member.
In addition, the present invention provides, in embodiments: an apparatus for forming images on a recording medium comprising: a) a charge-retentive surface to receive an electrostatic latent image thereon; b) a development component to apply a developer material to the charge-retentive surface to develop the electrostatic latent image to form a developed image on the charge-retentive surface; c) a transfer component for transferring the developed image from the charge-retentive surface to an intermediate transfer component; d) an intermediate transfer component for receiving the developed image from the transfer component and transferring the developed image to a transfix component; and e) a transfix component to transfer the developed image from the intermediate transfer component to a copy substrate and to fix the developed image to the copy substrate, the transfix component comprising: i) a transfix substrate comprising a material selected from the group consisting of fabric and metal, and thereover ii) an outer coating comprising a hybrid composition comprising polyamino polysiloxane and fluoroelastomer, and iii) a heating member associated with the transfix component.